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Technical Thematic Report No. 11. - Western Interior Basin Ecozone+ Evidence for key findings summary

Theme: Human/Ecosystem Interactions

Key finding 8
Protected areas

Theme: Human/ecosystem interactions

National key finding
Both the extent and representativeness of the protected areas network have increased in recent years. In many places, the area protected is well above the United Nations 10% target. It is below the target in highly developed areas and the oceans.

Before 1940, four small protected areas totalling 5 km2 were established in the WIBE by federal and provincial jurisdictions. Footnote 76 By 2009, 5,106 km2 (9% of the WIBE) was in 111 protected areas in IUCN categories I–IV. (Figure 26, Figure 27). Footnote 76 These categories include nature reserves, wilderness areas, and other parks and reserves managed for conservation of ecosystems and natural and cultural features, as well as those managed mainly for habitat and wildlife conservation. Footnote 77 In addition, 43 protected areas (0.07% of the WIBE) were in category VI for sustainable use by established cultural tradition. Footnote 77

In 2003, Canada and BC signed a Memorandum of Understanding to assess the feasibility of establishing a national park reserve in the South Okanagan–Lower Similkameen. The proposed park would represent the Interior Dry Plateau natural region, which is one of Parks Canada's 39 distinct natural regions and a natural region not yet represented in the national park system. In early 2012, however, the BC government withdrew from the feasibility assessment due to concerns that there was insufficient local support. Consequently, Parks Canada is not conducting any further work on the proposal at this time. Footnote 78

Figure 26. Area protected in the Western Interior Basin Ecozone+ from 1940 to 2009.
Data provided by federal and provincial jurisdictions, updated to May 2009.
Source: Environment Canada, 2009 Footnote 79using Conservation Areas Reporting and Tracking System (CARTS),
v.2009.05, 2009; Footnote 76 data provided by federal, provincial, and territorial jurisdictions

Area protected in the Western Interior

Long Description for Figure 26

This bar graph presents the growth of protected areas in the ecozone+.

Data for Figure 26 - Part 1
Year
protection
established
Cumulative area
protected (km2)
IUCN Categories
I-IV
1941732
1943747
1956749
1963853
19681197
19711212
19721224
19731465
19751500
19771501
19781510
19791518
19801519
19811527
19841528
19871711
19881725
19901729
19931770
19941778
19953144
19963780
19983855
19993868
20015020
20085106
Data for Figure 26 - Part 2
Year
protection
established
Cumulative area
protected (km2)
IUCN Categories
VI
19411
19431
19532
19553
195615
196122
196325
196527
197130
197533
198034
198135
198736
198837
199138
199639
199740
200443

E.C. Manning Park was established in 1941, Birkenhead Lake Park in 1963, Cathedral Park in 1968, several parks including Okanagan Mountain Park and Skagit Valley Park in 1973, Cascade Recreation Area in 1987, Eagle Hills Park, Marble Range Park, and Stein Valley Nlak'a'pamux Heritage Park in 1995, several parks including Bonaparte Park, Dunn Peak Park and Lac du Bois Grasslands Park in 1996, and several parks including Graystokes Park, Snowy Protected Area, and Spruce Lake Protected Area in 2001.

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Figure 27. The distribution of protected areas in the Western Interior Basin Ecozone+, 2009.
Not shown are four new provincial parks and one park expansion established in 2008.
Source: Environment Canada, 2009 Footnote 79 using Conservation Areas Reporting and Tracking System (CARTS),
v.2009.05, 2009; Footnote 76 data provided by federal, provincial, and territorial jurisdictions

distribution of protected areas

Long Description for Figure 27

This is a map shows protected areas. Large areas are located in the west with a few scattered in the centre of the ecozone+.

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Key finding 9
Stewardship

Theme: Human/ecosystem interactions

National key finding
Stewardship activity in Canada is increasing, both in number and types of initiatives and in participation rates. The overall effectiveness of these activities in conserving and improving biodiversity and ecosystem health has not been fully assessed.

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The WIBE, particularly in the South Okanagan, has benefited from the conservation and restoration activities of non-governmental organizations (NGOs), federal and provincial government agencies, city councils, First Nations, stewardship groups, and thousands of individuals.

Several local and regional stewardship organizations in the south and southwest of the WIBE work under the umbrella of the South Okanagan–Similkameen Conservation Program and in the north and central Okanagan under the Okanagan Collaborative Conservation Program. Although the Thompson region lacks a similar coordinating body, stewardship groups are also active in this region. Many other local, provincial, and national initiatives and organizations also operate throughout the WIBE.

Stewardship can play a key role in augmenting government-protected habitats of conservation concern. In 2005, 156 km2 of shrub-steppe and wetland/riparian habitats occurred on private land in the South Okanagan. Footnote 80 Of this, 7.5 km2(4.8%) had been acquired by The Nature Trust of BC, Ducks Unlimited Canada, The Land Conservancy of BC, or Nature Conservancy of Canada. An additional 12.6 km2(8.1%) were under covenant, in signed voluntary stewardship agreements, or were being actively stewarded by landowners without a signed agreement. Although there is no synthesis of stewardship activities and participation rates in the WIBE or across BC, information about stewardship projects can be obtained from the annual reports of many of the stewardship groups, as well as funders such as Environment Canada's Habitat Stewardship Program and the Habitat Conservation Trust Foundation.

Ecosystem conversion

Theme: Human/ecosystem interactions

Ecosystem conversion was initially identified as a nationally recurring key finding and information was subsequently compiled and assessed for the WIBE. In the final version of the national report, Footnote 3 information related to ecosystem conversion was incorporated into other key findings. This information is maintained as a separate key finding for the WIBE.

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Habitat loss

Ecosystem conversion resulting in habitat loss is the primary threat to biodiversity in the WIBE. Footnote 81 Footnote 82 Footnote 83Ecosystem conversion is the direct and complete conversion of natural landscapes such as forests, wetlands, or grasslands to landscapes of human uses (e.g., buildings, houses, parking lots, mines, reservoirs, and agricultural fields). Footnote 49Although no significant change in the extent of the WIBE's major biomes between 1985 and 2005 was detected using remote sensing Footnote 12, conversion was detected using larger-scale maps. Footnote 49Lower elevations had the highest rates (>22%) of terrestrial ecosystem conversion based on Baseline Thematic Mapping and Terrain Resource Information Management - Enhanced Base Maps from 1991–2001 (Figure 28).

Rates of ecosystem conversion in the WIBE were even greater historically. In the Okanagan and Lower Similkameen valleys, 12 ecosystems lost at least 33% of their area between 1800 and 2003, and 7 lost more than 60% (Figure 29). Footnote 20Most high-value riparian and wetland ecosystems and a substantial portion of low elevation grassland/shrubland ecosystems have been converted to other uses. Footnote 84

Figure 28: Percent of ecosystem conversion in the Western Interior Basin Ecozone+.
Source: adapted from Austin and Eriksson, 2009 Footnote 49Original map by Caslys Consulting Ltd., produced for Biodiversity BC based on imagery taken between 1991 and 2001; ecosystem conversion that occurred after the images were taken is not included.

map

Long Description for Figure 28

This map shows 10 categories of terrestrial ecosystem conversion:

Terrestrial ecosystem conversion (%)
0.00
0.01 - 0.13
0.14 - 0.67
0.68 - 1.66
1.67 - 3.49
3.50 - 6.99
7.00 - 12.12
12.13 - 21.95
21.96 - 43.00
43.01 - 100.00

Lower elevations had the highest rates (>22%) of terrestrial ecosystem conversion between 1991 and 2001. Areas along major rivers and around cities such as Kamloops and Kelowna had the highest levels of conversion.

More information about habitat loss can be found in the Theme: Biomes (the Key finding 1 - Forests section, the Key finding 2 - Grasslands section, the Key finding 3 - Wetlands section, and the Key finding 4 - Lakes and rivers section).

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Figure 29: Extent of the major ecosystems in the Okanagan and Similkameen valleys in 1800, 1938, and 2003.

graph

Long Description for Figure 29

This bar graph illustrates the following information:

Data for figure 29
YearBSNote1 of Figure Table 29 - Area (km2)DPNote2 of Figure Table 29 - Area (km2)CTNote3 of Figure Table 29 - Area (km2)PWNote4 of Figure Table 29 - Area (km2)CDNote5 of Figure Table 29 - Area (km2)GSNote6 of Figure Table 29 - Area (km2)ANNote7 of Figure Table 29 - Area (km2)SNNote8 of Figure Table 29 - Area (km2)FWNote9 of Figure Table 29 - Area (km2)LWNote10 of Figure Table 29 - Area (km2)BDNote11 of Figure Table 29 - Area (km2)ORNote12 of Figure Table 29 - Area (km2)
1800125231.774.3215376418.8198.9543.661951781522
1938104178.823.7812151.67266.5173.2532.2989.2468.944.972
200382.66154.282.647832.16164.6131.7813.3550.1729.6512.080.15
Per-cent Lost335058929340757033686184

Source: data from Lea, 2008 Footnote 20

Notes of Table Figure 29

Note 1 of Table Figure 29

Overall big sage shrub-steppe.

Return to note 1 referrer of table figure 29

Note 2 of Table Figure 29

Douglas fir – pine grass; PW: Ponderosa pine – blue bunch wheatgrass.

Return to note 2 referrer of table figure 29

Note 3 of Table Figure 29

Cattail marsh.

Return to note 3 referrer of table figure 29

Note 4 of Table Figure 29

Ponderosa pine – blue bunch wheatgrass.

Return to note 4 referrer of table figure 29

Note 5 of Table Figure 29

Black cottonwood - Red osier dogwood floodplain.

Return to note 5 referrer of table figure 29

Note 6 of Table Figure 29

Overall gentle slope grassland and Shrub-steppe.

Return to note 6 referrer of table figure 29

Note 7 of Table Figure 29

Antelope brush - needle and thread grass shrub-steppe.

Return to note 7 referrer of table figure 29

Note 8 of Table Figure 29

Big sage - needle and thread shrub-steppe.

Return to note 8 referrer of table figure 29

Note 9 of Table Figure 29

Idaho fescue – blue bunch wheatgrass grass steppe.

Return to note 9 referrer of table figure 29

Note 10 of Table Figure 29

Low elevation wetlands (marsh, shrub swamp, meadow, shallow open water).

Return to note 10 referrer of table figure 29

Note 11 of Table Figure 29

Water birch - Red osier dogwood riparian wetland swamp.

Return to note 11 referrer of table figure 29

Note 12 of Table Figure 29

Okanagan River.

Return to note 12 referrer of table figure 29

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Habitat fragmentation

Much of the low-lying, highly productive areas have been logged and/or converted to high human density areas or agriculture, or flooded by hydroelectric dams. Therefore, remaining low-elevation forests are often highly fragmented by roads and forest harvesting. Footnote 14 In addition to the actual loss and fragmentation of habitat, land conversion for agriculture and suburban development creates a "halo zone" around the developed areas where roads, soil disturbance, domestic animals, and invasive species threaten native species and natural processes.

The density of roads can be used as an indicator of habitat fragmentation. Major roads and highways may restrict the movement of less mobile terrestrial species; for example, roads in the major valleys interrupt connectivity of grassland habitats and increase mortality for animals such as reptiles and amphibians. Footnote 85 In 2005, the WIBE had a road density of 1.7 km of road/km2, the second highest among 10 regions of BC. Footnote 14Road densities in the WIBE are increasing, particularly in the eastern regions of the ecozone+ (Figure 30).

Figure 30: Road density and distribution in the Western Interior Basin Ecozone+ in 1995 and 2008.
The road density categories shown represent areas that are (1-blue) undeveloped, without roads, (2-green) minimally affected by few roads, (3-yellow) moderately developed, (4-orange) rural areas, and (5-red) urban areas.
Source: adapted with permission from BC Ministry of Forests, Mines and Lands, 2010. Footnote 19

map

Long Description for Figure 30

This figure includes two maps with five road density categories in km of road/km2 that include undeveloped, without roads (<0.1), minimally affected by few roads (0.1 to <0.6), moderately developed (0.6 to <2.0), rural areas (2.0 to <3.5), and urban areas (>3.5). Road density increases from 1995 to 2008, particularly throughout the Okanagan in the eastern part of the ecozone+.

Urban, suburban, and agricultural development pressures will continue to fragment the WIBE's low elevation ecosystems. Ecosystem and habitat fragmentation is of particular concern in the southern Okanagan, which is the northern extension of the Great Basin desert of the United States. If well-managed, the southern Okanagan can provide a corridor for the north–south movement of species as the climate changes. Footnote 86 The two main river systems, the Okanagan and the Fraser, also provide corridors for migration and dispersal of riparian and aquatic species. In addition to allowing movement of native species, however, these corridors may facilitate the invasion of non-native species. Footnote 87

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Urban areas

In 2010, Footnote 88 the four largest urban settlements in the WIBE were Kelowna (121,000), Kamloops (87,000), Vernon (39,000), and Penticton (33,000). This is one of the fastest growing regions in Canada, and population growth is expected to continue (Table 4).

Table 4. Projected population growth in four regional districts in the Western Interior Basin Ecozone+. Footnote 89
Regional district20082035 (projected)Percent growth
Thompson-Nicola Table Footnote a130,132163,68120.5%
Okanagan-Similkameen82,43692,16010.5%
Central Okanagan180,114263,89231.7%
North Okanagan81,932103,00520.5%

Table Footnote

Footnote 1

Thompson-Nicola Regional District is partially in the WIBE and partially in the Montane Cordillera Ecozone+.
Source: BC Statistics and Statistics Canada, 2007

Return to Footnote a referrer

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Ecosystems in these cities have been dramatically altered. Overall loss was highest in Kelowna (Figure 31) and 100% of water birch–red-osier dogwood ecosystems were lost in Vernon. Footnote 20

Figure 31: Extent and loss of ecosystems in the City of Kelowna in 1800, 1938, and 2001.Source: Lea, 2008Footnote 20

graph

Long Description for Figure 31

This bar graph illustrates the following information:

Data for figure 31
YearPW - Area (km2)Note 1 of Figure Table 31OW - Area (km2)Note 2 of Figure Table 31CD - Area (km2)Note 3 of Figure Table 31FW - Area (km2)Note 4 of Figure Table 31BD - Area (km2)Note 5 of Figure Table 31
1800451.71133731
1938311.555.588.584.98
2001120.321.882.461.17
Percent lost8174939686

Notes of Table Figure 31

Note 1 of Table Figure 31

Ponderosa pine – blue-bunch wheat-grass gentleslope.

Return to note 1 referrer of table figure 31

Note 2 of Table Figure 31

Shallow Open Water.

Return to note 2 referrer of table figure 31

Note 3 of Table Figure 31

Black Cottonwood – red-osier dogwood.

Return to note 3 referrer of table figure 31

Note 4 of Table Figure 31

Idaho fescue – bluebunch wheatgrass.

Return to note 4 referrer of table figure 29

Note 5 of Table Figure 31

Water Birch – red-osier dogwoodwetland shrub swamp.

Return to note 5 referrer of table figure 31

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Key finding 10
Invasive non-native species

Theme: Human/ecosystem interactions

National key finding
Invasive non-native species are a significant stressor on ecosystem functions, processes, and structure in terrestrial, freshwater, and marine environments. This impact is increasing as numbers of invasive non-native species continue to rise and their distributions continue to expand.

Species that inhabit areas outside their natural range are known as alien or non-native species. Most non-native species do not become established, are not detrimental, and can even be beneficial. Footnote 90 Invasive non-native species, however, cause considerable harm to our environment, the economy, or to society. Footnote 91 The ecological impacts of invasive non-native species are diverse. Non-native animals may outcompete, consume, or transmit diseases to native animals. Non-native plants can decrease the abundance of native plants, increase ecosystem productivity, change fire regimes, and alter the rate of nutrient cycling. Footnote 92 Economic impacts of invasive non-native species include lowered real estate values, reduced quality of fish habitat, clogged irrigation pipes, decreased quality of forage by wildlife and livestock, and reduced recreational opportunities. Footnote 93 The costs can be substantial. For example, six invasive plant species in BC had a combined economic impact of $65 million in 2008 and this was projected to increase to $139 million by 2020. Footnote 93 Invasive non-native species can also be harmful to human health and to domestic animals, such as hound's tongue (Cynoglossum officinale) which can cause liver damage to livestock.

Biocontrol programs use select non-native species to control other non-native species. By 1994, 103 non-native insects, 5 protozoans, 1 fungus, and 2 viruses were introduced to BC to control insect pests, as well as 59 species of insects, fungi, and nematodes to control weeds. Footnote 94 Other species have been introduced in biocontrol programs since then. Footnote 95 Footnote 96 A lengthy research process that includes quarantines and controlled trials precedes the introduction of biocontrol agents. Footnote 97

The WIBE has a substantial number of non-native terrestrial and aquatic plants and animals (Figure 32). The three biogeoclimatic zones identified as of conservation concern each have more than 100 non-native species associated with them (Table 5).

Table 5. The proportion of each biogeoclimatic zone in the Western Interior Basin Ecozone+and the number of terrestrial non-native plant and animal species associated with each zone. Footnote 14 Footnote 49 Footnote 98
Biogeoclimatic zoneProportion of
each zone in WIBE
Terrestrial non-native species throughout
BC associated with each zone
Interior Douglas-fir Table Footnote b41%335
Montane Spruce22%182
Engelmann Spruce--Subalpine Fir21%232
Ponderosa Pine Table Footnote b5%187
Interior Mountain-heather Alpine4%44
Bunchgrass Table Footnote b3%148
Interior Cedar–Hemlock3%265
Coastal Western Hemlock1%579

Table Footnote

Footnote 2

Zones identified as being of conservation concern
Source: adapted from Austin and Eriksson, 2009 and BC Ministry of Forests, Mines and Lands, 2010

Return to Footnote b referrer

Figure 32: Number of terrestrial and freshwater non-native species in Western Interior Basin Ecozone+, 2008.
Source: adapted from Austin and Eriksson, 2009 Footnote 49Original map by Caslys Consulting Ltd., produced for Biodiversity BC.

map

Long Description for Figure 32

This map shows that non-native species are concentrated along major rivers and near cities such as Kamloops and Kelowna which can have a high of 12-92 non-native species.

Invasive terrestrial plants

In 2009, the provincial Invasive Alien Plant Program (IAPP) listed 83 invasive plants in the WIBE, Footnote 99 a conservative estimate because invasive plant inventories have not been conducted throughout the ecozone+. Footnote 100

Many of these invasive plants became established in the WIBE 50–100 years ago (Table 6). Footnote 101 Species such as Kentucky bluegrass (Poa pratensis), smooth brome (Bromus inermis), cheatgrass (B. tectorum), yellow salsify (Tragopogon dubius), diffuse and spotted knapweed (Centaurea spp.), sulfur cinquefoil (Potentilla recta), and others are widespread throughout WIBE grasslands. Footnote 38 Footnote 102 Footnote 103 Footnote 104 Purple loosestrife (Lythrum salicaria), yellow iris (Iris pseudacorus), and common reed (Phragmites australis ssp. australis) have invaded wetlands and marshes. Footnote 105 Footnote 106

Biological, chemical and mechanical control are used to manage invasive terrestrial plants. For example, knapweed seedhead weevils (Larinus obtusus) introduced as biocontrol agents in the early 1990s decreased the number of knapweed flower stems per area in the southern Okanagan. Footnote 96 In the Thompson–Nicola region, the Southern Interior Weed Management Committee encourages chemical control of invasive species by sharing the treatment costs. Footnote 107Organizations throughout the region organize stewardship activities that include the mechanical removal of invasive species and the regional districts of the Okanagan–Similkameen, North Okanagan, and Central Okanagan have by-laws supporting the management of invasive species.

Table 6. Date of first records of selected non-native plant arrivals in BC and in the Okanagan. Footnote 20 Footnote 31
Scientific nameCommon nameEarliest record in BCEarliest record in the Okanagan
Arctium lappaGreat burdock18951933
Arctium minusCommon burdock19091917
Bromus tectorumCheatgrass18901912
Centaurea diffusaDiffuse knapweed19361939
Centaurea maculosaSpotted knapweed18931944
Cirsium arvenseCanada thistle18941913
Cuscuta pentagonaDodder1911Late 1970s
Cynoglossum officinaleHound's tongue19221922
Echium vulgareBlueweed19171918
Hypericum perforatumSt. John's wort19131950
Linaria genistifolia var.
dalmatica
Dalmatian toadflax19401952
Lythrum salicariaPurple loosestrife18971963
Potentilla rectaSulphur cinquefoil19141940
Senecio jacobaeaTansy ragwort19131991
Tribulus terrestrisPuncturevine19741974

Source: Lea, 2007 Footnote 20 Footnote 31

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Invasive terrestrial animals

Many invasive terrestrial animals were intentionally introduced. Ring-necked pheasants (Phasianus colchicus), grey (Hungarian) partridges (Perdix perdix), California quail (Callipepla californica), wild turkeys (Melagris gallopavo), and chuckar partridges (Alectoris chukar) were introduced for hunting and have established stable populations in the WIBE. Footnote 108 Eastern grey squirrels (Sciurus carolinensis), feral horses (Equus caballus), and feral cats (Felis domesticus) have also invaded the sensitive ecosystems of the WIBE. Footnote 109

Invasive aquatic species

Sixteen species of non-native fish have been introduced to the rivers and lakes of the WIBE. Footnote 110 The introductions began in 1929 with the greatest number of introductions occurring in the 1940s (Figure 34). Some non-native fish were introduced to BC for angling and others were stocked in Washington State and later invaded BC waters. Osoyoos Lake has the largest number of non-native fish species (10 species confirmed and 3 possibly present) of the Okanagan valley floor lakes. Footnote 111Other lakes in the WIBE, such as Shuswap Lake, have introduced yellow perch (Perca flavescens). Footnote 112

The Freshwater Fisheries Society of BC regularly stocks some lakes with strains of rainbow trout that are not native to the particular lake. Footnote 113 Their effect on native fish has not been well studied in the WIBE, but rainbow trout stocking in previously fishless lakes caused amphibians [long-toed salamander (Ambystoma macrodactylum), Columbia spotted frog (Rana luteiventris), and Pacific treefrog (Hyla regilla)] to decline by 64% in the Thompson–Nicola region. Footnote 114

Mysis shrimp (also known as mysids) are small, freshwater shrimp that were introduced to Okanagan Lake in 1966 to provide a food source for rainbow trout (Oncorhynchus mykiss) and kokanee. Footnote 45Kokanee declined, however, due to the loss of kokanee spawning habitat, nutrient imbalances in the lake that led to a decline in lake productivity, overfishing, and competition between mysids and kokanee for preferred cladoceran zooplankton (e.g., Daphnia). Footnote 115 Footnote 116 Footnote 117Mysids have a daily migration pattern through the water column that limits the amount of time they are available for consumption by kokanee. Footnote 45Mysids live near the bottom of the lake during the day (100–120 m), move upward after dark to feed on zooplankton near the surface (20 m), and then migrate back down before dawn. Whether the consumption of daphnia by mysids is substantial enough to explain the long-term decline in kokanee salmon stocks in Okanagan Lake, however, remains unresolved. Footnote 118 Mysids also moved downstream to Skaha and Osoyoos lakes. In shallower lakes, like Skaha Lake, kokanee have more opportunities to eat mysids. Footnote 45

Mysid biomass estimates in Okanagan Lake have ranged from 2,700 to 5,700 tonnes. Footnote 119 A fishery was opened in 1999 to provide mysids for the aquarium and aquaculture industries. Footnote 45The efficiency of capturing mysids improved from 2000 to 2004 and harvest levels peaked at 78 tonnes in 2001 (Figure 33). To impact the population, however, harvest needs to exceed 1,000 tonnes and so new markets for mysids are needed before the WIBE shrimp fishery can expand. Footnote 117

Figure 33. The total mysid catch (metric tonnes of wet weight) from the shrimp fishery in Okanagan Lake from 1999 to 2005.
Source: Rae and Andrusak, 2006 Footnote 45and Andrusak and White, 2008 Footnote 119

map

Long Description for Figure 33

This bar graph shows the following information:

Data for figure 33
YearTotal Mysid Catch
(metric tonnes of wet weight)
199912.5
200015.1
200177.9
200249.8
200345.7
200437.3
200531.8
200622
200729.4

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Since the early 1900s, 30 non-native aquatic plant species are known to have been introduced to the WIBE (Figure 34). Footnote 110 In the 1970s, one of the most problematic aquatic plants for the large Okanagan lakes was Eurasian water-milfoil (Myriophyllum spicatum). Footnote 120 Some plants included in Figure 34 are terrestrial species that can affect aquatic environments. For example, saltcedar (Tamarix ramosissima) has deep taproots that consume large amounts of water and leaves that excrete salt, which inhibit native riparian plants. Although saltcedar was not considered a problem in the WIBE in 2010, some BC nurseries sell it as an ornamental and it was identified at a site near Penticton. Footnote 121

Figure 34: The cumulative number of fish and aquatic plants introduced to the Western Interior Basin Ecozone+ from the 1900's to 2000's.
Source: Herborg, 2011 Footnote 110

graph

Long Description for Figure 34

This bar graph shows the following information:

Data for figure 34
DecadeFishPlants
1900s01
1910s04
1920s15
1930s29
1940s911
1950s1011
1960s1114
1970s1223
1980s1225
1990s1328
2000s1430

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Invasive pathogens and disease

Similar to non-native plants and animals, non-native pathogens are species that have been moved from their native range and introduced to a new area. Non-native pathogens include bacteria, fungi, nematodes, other microscopic eukaryotes, and viruses, which can cause sickness or death in other species. This can alter the species composition of ecosystems. For example, white pine blister rust (Cronartium ribicola) arrived in BC around 1910, reached the interior about 1930, and is responsible for the severe reduction of western white pine (Pinus monticola) in the WIBE. Efforts to eradicate the rust's intermediate hosts--currants and gooseberries - did not control the blister rust. Footnote 122

Key finding 11
Contaminants

Theme: Human/ecosystem interactions

National key finding
Concentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.

There were no ecozone+-level monitoring programs for contaminants in the WIBE, only localized research studies in birds [ospreys (Pandion haliaetus) and American robins (Turdus migratorius)] and fish. For example, in the Thompson region in the early 1990s, organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury residues in the eggs and blood of ospreys were higher downstream than upstream of a pulp mill. Footnote 123 Also in the 1990s, American robins nesting in orchards had higher DDT residue levels to those outside of orchards, even 20 years after the banning of DDT. However, reproduction by orchard robins was unaffected. Footnote 124 Footnote 125 In contrast, concentrations of mercury and DDT declined in rainbow trout in Okanagan Lake in the 2000s (Figure 35). Footnote 126 Of four fish species sampled from 2000 to 2006, lake trout (Salvelinus namaycush) had DDT concentrations ranging from 1 to 16 parts per million (ppm), and rainbow trout, kokanee, and largemouth bass (Micropterus salmoides) all had concentrations less than 1 ppm. Health Canada's human consumption guidelines are less than 0.5 ppm for both mercury and DDT. Footnote 126

Figure 35: Total mercury and DDT in individual Okanagan Lake rainbow trout from 1970 to 2005.
Source: Rae and Jensen, 2007 Footnote 126

graph

Long Description for Figure 35

These are two scatter plots. Total mercury in parts per million were highest, approximately 0.9 ppm, for confirmed wet weight measurements in 1971 and approximately 0.75 ppm of weight, measurement method unknown (wet or dry), in 1974. Confirmed wet weight measurements declined below the Health Canada consumption guideline of 0.5 in 1990 and were down to approximately 0.15 in 2005. DDT in parts per million were highest, approximately 11.5 ppm, for confirmed wet weight measurements in 1971 and approximately 15 ppm of weight, measurement method unknown (wet or dry), in 1970. Confirmed wet weight measurements declined below the Health Canada consumption guideline of 5 in 1988 and were down to approximately 1 in 2005.

Key finding 12
Nutrient loading and algal blooms

Theme: Human/ecosystem interactions

National key finding
Inputs of nutrients to both freshwater and marine systems, particularly in urban and agriculture-dominated landscapes, have led to algal blooms that may be a nuisance and/or may be harmful. Nutrient inputs have been increasing in some places and decreasing in others.

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Residual soil nitrogen on agricultural lands

The WIBE is classed as having low residual soil nitrogen (Figure 36), which is an indicator of "unused" nitrogen in the soil at the end of an agricultural crop season. Footnote 127 Nitrogen inputs to the soil generally decreased from 1981 to 2006, although they increased in 2001. The decline from 2001 to 2006 was due to fewer livestock and less nitrogen from manure, decreased use of nitrogen fertilizers, and decreased nitrogen fixation by legumes. Nitrogen outputs, which include crop removal, ammonia volatilization, and denitrification, also decreased over this period due to changing crop acreages and decreasing hay yields. The net result was that the WIBE was the only agricultural ecozone+ in Canada where residual soil nitrogen decreased(20.6 kg N ha-1 in 1981 to 16.5 kg N ha-1 in 2006), although some local areas were stable or increased within the WIBE (Figure 37). Footnote 127

Figure 36: Residual soil nitrogen classes in 2006.
Source: Drury et al., 2011 Footnote 127

map

Long Description for Figure 36

This map shows locations of residual soil nitrogen in kg N/ha. Very high risk (≥40) is located in the south, high risk (30.0-39.9) and moderate (20.0-29.9) in the northeast and north central, low risk (9.9-19.9) throughout the central and very low risk (0.0-9.9) in the centre of the ecozone+.

Figure 37: Change in residual soil nitrogen class for the Western Interior Basin Ecozone+ and parts of adjacent ecozones+ between 1981 and 2006.
Source: Drury et al., 2011 Footnote 127

map

Long Description for Figure 37

This map shows that nitrogen inputs to the soil generally decreased from 1981 to 2006, although they increased in 2001. The WIBE was the only agricultural ecozone+ in Canada where residual soil nitrogen decreased (20.6 kg N/ha in 1981 to 16.5 kg N/ha in 2006). Central parts of the ecozonez+were stable or decreased. Increases were evident in the south central part of the ecozone+.

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Nutrient loading to lakes

Pollution due to nutrient loading caused algal blooms in some of the large Okanagan Valley lakes in the 1960s and 1970s. Footnote 128 Due to reductions in phosphorus inputs from agricultural sources, the total phosphorus load to Okanagan Lake has decreased by 30% and improved sewage treatment resulted in a 95% reduction of the point source phosphorus load between 1970 and 2001. Footnote 128The nutrient load was also reduced in Skaha Lake (Figure 38) and Osoyoos Lake (data not shown) with a concomitant decrease in chlorophyll a (a measure of the phytoplankton concentration) and increase in dissolved oxygen (which improves conditions for salmonids and other species). Footnote 48 More information about lakes and fish populations can be found in the Lakes and rivers section on page 28 and the Fish section on page 75.

There was deterioration near towns such as Salmon Arm by 2001. Footnote 129 In 2002, a new liquid waste management plan was ordered to improve sewage treatment. Annual nutrient loads are increasing in Mara Lake due to anthropogenic changes in the Shuswap River drainage basin. Forestry, agriculture, and urbanization have increased total phosphorus and nitrogen in the lake. Footnote 130 The federal and provincial governments announced a drinking water treatment plant for Sicamous and Mara lakes in 2013. Footnote 131

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Figure 38: Changes in nutrient loading in Skaha Lake, 1968-2009.
Left axis is total phosphorus (total P) and chlorophyll a (chlor a); right axis is dissolved oxygen (DO).
Source: updated from Jensen and Epp, 2002 Footnote 48

graph

Long Description for Figure 38

This three line graph of nutrient loading in Skaha Lake shows the following information:

Data for figure 38
YearTotal phosphorus
(ug/L)
Chlorophyll a
(ug/L)
Dissolved oxygen
(mg/L)
196822.000  
196931.700  
197045.000  
197118.000  
1972   
197312.000  
197418.000  
197512.000  
197611.000  
197711.000 4.10
197821.00016.100 
197930.750 4.00
198029.00019.7005.60
198123.50012.900 
198228.0008.5255.30
198324.00010.2006.80
198426.00011.3006.40
198517.4296.2714.50
198616.0009.300 
198723.5007.2502.60
198827.0005.1006.50
198920.50010.6007.60
199018.00017.6007.20
199113.00011.4008.40
199212.0007.7005.80
199312.0008.5006.76
19949.00015.7005.74
19953.0008.1007.30
19968.0007.8006.35
199710.0005.2008.40
19986.0005.4007.60
199910.0000.7508.24
20009.0003.2007.70
200112.0009.7006.20
20022.000  
200310.0004.8007.01
20046.0007.80010.16
20054.0004.0006.92
20069.0001.0007.85
20077.00012.2007.92
200810.0004.0507.75
20096.0003.0008.50

Key finding 13
Acid deposition

Theme: Human/ecosystem interactions

National key finding
Thresholds related to ecological impact of acid deposition, including acid rain, are exceeded in some areas, acidifying emissions are increasing in some areas, and biological recovery has not kept pace with emission reductions in other areas.

Acid deposition was an issue of interest in BC in the 1980s; precipitation chemistry and data on acid levels were collected for several years at monitoring stations in Kamloops and Kelowna. The soils and lakes in the WIBE are considered at low risk from small changes in rain pH. Footnote 132 Coastal BC lakes were monitored from 1984 to 1994 and acidity did not change, Footnote 133 so it is probable that lakes in the WIBE did not change either.

Key finding 14
Climate change

Theme: Human/ecosystem interactions

National key finding
Rising temperatures across Canada, along with changes in other climatic variables over the past 50 years, have had both direct and indirect impacts on biodiversity in terrestrial, freshwater, and marine systems.

Climatic variables

Spring, summer, and winter temperatures increased from 1950 to 2007 across the WIBE (Table 7, Figure 39). Spring and fall precipitation increased, with some variability around the ecozone+, and winter precipitation decreased throughout the ecozone+(Figure 40). The duration of snow cover (Figure 41) and the amount of precipitation falling as snow decreased. With these changes, the growing season also started earlier and was longer at some stations.

Table 7. Summary of changes in climatic variables in the WIBE, 1950–2007. Footnote 134
Climatic variableOverall ecozone+ trend (1950–2007)Comments and regional variation
Temperaturerise of 1.9℃ in spring, 1.7℃ in summer,
and 2.1℃ in winter
Trends are consistent across ecozone+
Precipitationrise of 40% in spring precipitation
and 42% in fall precipitation
decrease of 22% in winter precipitation
rise in spring precipitation at a majority of
the stations
rise in fall precipitation concentrated in the
southeast
rise in summer precipitation at three
stations in the central east
decrease in winter precipitation spread
throughout the ecozone+
Snowdecrease in the amount of precipitation
falling as snow (9.8% decrease in the
absolute ratio)
decrease in snow duration in the late-winter
and spring (February to July)
No overall trend in snow depth
decrease in precipitation falling as snow across
the ecozone+
decrease in snow duration in the late-winter and
spring (February to July) by >20 days at
three of six stations
rise in maximum snow depth at Grand Forks
Growing seasonNo overall trend in growing seasonGrowing season was longer at two of
four stations (16.6 and 22.1 days)
Growing season started 16 days earlier in
Kamloops

Only significant trends (p<0.05) are included
Source: Zhang et al., 2011 and supplementary data provided by the authors

Figure 39: Change in mean temperature, 1950–2007 for a) spring (March–May), b) summer (June–August), c) fall (September–November), and d) winter (December–February)
Source: Zhang et al., 2011 Footnote 134 and supplementary data provided by the authors

map

Long Description for Figure 39

This set of four maps depicts change in mean annual temperature in spring, summer, fall, and winter in cities and towns in the WIBE between 1950 and 2007. Spring temperature increases were reported for Vernon (2.3℃), Kamloops and Princeton (1.9℃), and Summerland (1.7℃). Summer temperature increases were reported for Summerland (2.1℃), Vernon (2.0℃), Kamloops (1.5℃), and Princeton (1.3℃). Winter temperature increases were reported for Kamloops (2.6℃), Vernon (2.2℃), and Princeton (2.0℃). There were no significant increases detected for fall.

Figure 40. Change in the amount of precipitation, 1950–2007 for a) spring (March–May), b) summer (June–August), c) fall (September–November), and d) winter (December–February).
Expressed as a percentage of the 1961–1990 mean.
Source: Zhang et al., 2011 Footnote 134 and supplementary data provided by the authors

map

Long Description for Figure 40

This set of four maps depicts change in mean annual temperature in spring, summer, fall, and winter in cities and towns in the WIBE between 1950 and 2007. In spring, precipitation increased in Darfield (51.0%), Kamloops (52.1%), Westwold (81.7%), Merritt (62.5%), Vernon (56.7%), Okanagan Centre (59.6%), Kelowna (63.7%), Summerland (59.8%), Hedley (72.5%), Keremeos (87.9%) and Penticton (32.6%). In summer, precipitation increased in Westwold (48.3%), Vernon (51.3%) and Kelowna (66.8%). In fall, precipitation increased in Vernon (58.6%), Kelowna (43.1%), Pentiction (48.3%), Hedley (73.9%) and Keremeos (25.5%) and decreased in Lajoie Dam (-132.8%). In winter, decreases were observed in Shalalth (-92.3%), Kamloops (-29.8), Lytton (-49.6), Merritt (-68.5%), Kelowna (-40.7%), Joe Rich Creek (-40.9%), Princeton (-45.0%) and Beaverdell (-71.9%).

Figure 41: Change in snow duration, the number of days with ≥2 cm of snow on the ground, 1950–2007 in a) the first half of the snow season (August–January), which indicates changes in the start date of snow cover, and b) the second half of the snow season (February–July), which indicates changes in the end date of snow cover.
Source: Zhang et al., 2011 Footnote 134 and supplementary data provided by the authors

map

Long Description for Figure 41

This set of two maps shows there were no changes in the first half of the snow season; however, in the second half, the snow season ended earlier in Kamloops (-21.6 days), Westwold (-39.4 days), and Joe Rich Creek (-46.2 days).

Hydrology and climate analyses

Stream flow, temperature, and precipitation have changed between 1961–1982 and 1983–2003. These changes were analyzed using data from five hydrology stations clustered in the south of the WIBE. Footnote 135 There were stations located in the northern sections of the WIBE, but they were classified to the Montane Cordillera Ecozone+because membership was based on watershed areas, rather than station location. Footnote 135 The results from the Similkameen and Kettle rivers are provided as representative examples of the southwest and southeast, respectively. Both stations recorded earlier onsets of spring freshet, lower flows in late summer, and higher flows in early winter (Figure 42, Figure 43). The Kettle River station also recorded lower flows in early fall (Figure 43). These changes are driven by climate change as well as land alteration and conversion. Footnote 135 See also the Large lakes and Streams sections on pages 28 and 30, respectively.

Figure 42: Annual stream flow, temperature, and precipitation, comparing 1961–1982 (paler line) and 1983–2003 (darker line) for the Similkameen River at Princeton (Station 08NL007)
Source: Cannon et al., 2011 Footnote 135

Annual stream flow, temperature, and precipitation

Long Description for Figure 42

These three line figures compare earlier and later timespans from January to December for the onset of stream flow (m3/s), temperature, and precipitation. Streamflow showed that the onset of spring freshet occurred earlier, that flows were lower in late summer, and that flows were higher flows in early winter. Temperature (℃) was higher in more recent years in the spring and precipitation (mm) was lower in the spring, higher in the summer, and lower in the winter.

Figure 43: Annual stream flow, temperature, and precipitation, comparing 1961–1982 (paler line) and 1983 -2003 (darker line) for the Kettle River at Ferry (Station 08NN013)
Source: Cannon et al., 2011 Footnote 135

Annual stream flow, temperature

Long Description for Figure 43

These three line figures compare earlier and later timespans from January to December for the onset of stream flow (m3/s), temperature, and precipitation. Streamflow showed that the onset of spring freshet occurred earlier, that flows were lower in late summer and early fall, and that flows were higher flows in early winter. There was no difference in temperature (℃) and precipitation (mm) was higher in the spring and early summer.

Future climate predictions

Climate change in the WIBE is expected to have a range of effects on ecosystems and species such as:

  • the alteration of the distribution, extent, and composition of forests; Footnote 136
  • the loss of some ecosystems including some wetland and alpine areas; Footnote 137
  • a general expansion of species' ranges northwards and upslope; Footnote 137
  • an increase in growing days; Footnote 137 and
  • a more rain-dominated stream flow for the Okanagan Basin with earlier peak runoff and an extended period of low flows in summer. Footnote 138 Footnote 139 Footnote 140

Key finding 15
Ecosystem services

Theme: Human/ecosystem interactions

National key finding
Canada is well endowed with a natural environment that provides ecosystem services upon which our quality of life depends. In some areas where stressors have impaired ecosystem function, the cost of maintaining ecosystem services is high and deterioration in quantity, quality, and access to ecosystem services is evident.

Ecosystem services in the WIBE include water (a provisioning service), crop pollination (a regulating service), and nutrient cycling (a supporting service); these are necessary for food production and potable water. Other provisioning services harvested commercially or recreationally including forests, wildlife, and fish. The WIBE's ecosystems also provide cultural services, which include educational, recreational, and spiritual experiences.

Ecosystem services in the WIBE have not been systematically quantified for their economic value. However, a project initiated in 2012–13 will estimate the value of ecosystem services supported by the last remaining natural (unchannelled) section of the Okanagan River. Footnote 141


Content Footnote

Footnote 3

Federal, Provincial and Territorial Governments of Canada. 2010. Canadian biodiversity strategy: ecosystem status and trends 2010. Canadian Councils of Resource Ministers. Ottawa, ON. vi + 142 p.

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Pitt, M. and Hooper, T.D. 1994. Threats to biodiversity of grasslands in British Columbia. In Biodiversity in British Columbia: our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 20. pp. 279-292.

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Footnote 12

Ahern, F., Frisk, J., Latifovic, R. and Pouliot, D. 2011. Monitoring ecosystems remotely: a selection of trends measured from satellite observations of Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 17. Canadian Councils of Resource Ministers. Ottawa, ON.

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Footnote 14

Austin, M.A., Buffett, D.A., Nicolson, D.J., Scudder, G.G.E. and Stevens, V. (eds.). 2008. Taking nature's pulse: the status of biodiversity in British Columbia. Biodiversity BC. Victoria, BC. 268 p.

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Footnote 19

BC Ministry of Forests, Mines and Lands. 2010. The state of British Columbia's forests: third edition. Forest Practices and Investment Branch, British Columbia Ministry of Forests, Mines and Lands. Victoria, BC. xiii + 308 p.

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Footnote 20

Lea, T. 2008. Historical (pre-settlement) ecosystems of the Okanagan Valley and Lower Similkameen Valley of British Columbia: pre-European contact to the present. Davidsonia 19:3-36.

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Footnote 38

Gayton, D.V. 2004. Native and non-native plant species in grazed grasslands of British Columbia's southern interior. BC Journal of Ecosystems and Management 5:51-59.

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Footnote 46

BC River Forecast Centre. 2011. Unpublished analysis of data obtained from the Water Survey of Canada: Normal analysis and net inflow calulations for Okanagan Lake 1921-2011 [online]. Water Survey of Canada. (accessed 2 February, 2012).

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Footnote 49

Austin, M.A. and Eriksson, A. 2009. The biodiversity atlas of British Columbia. Biodiversity BC. 135 p.

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Footnote 76

CCEA. 2009. Conservation Areas Reporting and Tracking System (CARTS), v.2009.05 [online]. Canadian Council on Ecological Areas. http://ccea.org/en_carts.html (accessed 5 November, 2009).

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Footnote 77

IUCN. 1994. Guidelines for protected area management categories. Commission on National Parks and Protected Areas with the assistance of the World Conservation Monitoring Centre, International Union for Conservation of Nature. Gland, Switzerland and Cambridge, UK. x + 261 p.&lt;&lt;/p&gt;

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Footnote 78

Parks Canada. 2011. South Okanagan-Lower Similkameen National Park Reserve feasibility assessment [online]. Parks Canada. (accessed 7 May, 2013)

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Footnote 79

Environment Canada. 2009. Unpublished analysis of data by ecozone+ from: Conservation Areas Reporting and Tracking System (CARTS), v.2009.05 [online]. Canadian Council on Ecological Areas. http://ccea.org/en_carts.html (accessed 5 November, 2009).

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Footnote 80

Dyer, O. and Wood, C. 2007. Conservation assessment for South Okanagan Similkameen Conservation Program (SOSCP) priority ecosystems. British Columbia Ministry of Water, Land and Air Protection. Penticton, BC. Unpublished report.

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Harding, L.E. and McCullum, E. 1994. Overview of ecosystem diversity. In Biodiversity in British Columbia: our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 18. pp. 227-244.

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Seaton, R. 2003. Ecosystem at risk: antelope brush restoration. Osoyoos, BC. 28 March, 2003. Edited by Seaton, R. Society for Ecological Restoration, BC Chapter and The Desert Centre.76 p. Conference proceedings.

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Bezener, A., Dunn, M., Richardson, H., Dyer, O., Hawes, R. and Hayes, T. 2004. South Okanagan-Similkameen conservation program: a multi-partnered, multi-species, multi-scale approach to conservation of species at risk. In Proceedings of the Species at Risk 2004 Pathways to Recovery Conference. Victoria, BC, 2-6 March, 2004. Edited by Hooper, T.D. Pathways to Recovery Conference Organizing Committee. Victoria, BC.

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Footnote 84

Interior Columbia Basin Ecosystem Management Project. 2007. Interior Columbia Basin ecosystem management project. [online].United States Department of Agriculture Forest Service and Pacific Northwest Research Station. (accessed 28 October, 2009).

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Demarchi, D., Kavanagh, K., Sims, M. and Mann, G. 2001. Okanagan dry forests (NA0522) [online]. World Wildlife Fund and Island Press. (accessed 3 March, 2011).

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Footnote 86

Vold, T. 1992. The status of wilderness in British Columbia: a gap analysis. Ministry of Forests. Victoria, BC.

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Harding, L.E. 1994. Exotic species in British Columbia. In Biodiversity in British Columbia: our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 17. pp. 159-226.

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Footnote 88

BC Statistics. 2011. Data tables for municipalities, regional districts, and development regions, 2006-2010 [online]. BC Statistics. (accessed 10 September, 2011).

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BC Statistics. 2007. British Columbia municipal census populations, 1921-2006: Victoria [online]. BC Statistics.
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Schlaepfer, M.A., Sax, D.F. and Olden, J.D. 2011. The potential conservation value of non-native species. Conservation Biology 25:428-437.

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Frid, L., Knowler, D., Murray, C., Myers, J. and Scott, L. 2009. Economic impacts of invasive plants in BC. Invasive Plant Council of BC and ESSA Technologies Ltd. Vancouver, BC. 105 p.

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Smith, R. 1994. Effects of alien insects and microorganisms on the biodiversity of British Columbia's insect fauna. In Biodiversity in British Columbia: our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 17. pp. 190-219.

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Footnote 95

Myers, J.H. 2007. How many and what kind of biocontrol agents: a case study with diffuse knapweed. In Biocontrol: A global perspective. Edited by Vincent, C., Goettel, M.S. and Lazarovits, G. CAB International. Wallingford, Oxfordshire, UK. pp. 70-79.

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Myers, J.H., Jackson, C., Quinn, H., White, S.R. and Cory, J.S. 2009. Successful biological control of diffuse knapweed, Centaurea diffusa, in British Columbia, Canada. Biological Control 50:66-72.

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BC Ministry of Agriculture. 2012. Biological weed control in British Columbia [online]. British Columbia Ministry of Agriculture.(accessed 6 February, 2012).

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BC Ministry of Forests, Mines and Lands. 2010. The state of British Columbia's forests, third edition. Forest Practices and Investment Branch, British Columbia Ministry of Forests, Mines and Lands. Victoria, BC. xiii + 308 p.

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Footnote 100

Miller, V. 2010. Personal communication. Invasive Plant Officer, Ministry of Forests, Lands and Natural Resource Operations. Nelson, BC.

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Footnote 101

Cannings, R., Durance, E. and Scott, L.K. 1988. South Okanagan ecosystem recovery plan: scientific assessment. Cannings Holm Consulting. Naramata, BC. 122 p.

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BC Ministry of Agriculture. 2007. Knapweed - its cost to British Columbia [online]. British Columbia Ministry of Agriculture

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Harding, L.E. 1994. Introduced wildflowers and range and agricultural weeds in British Columbia. In Biodiversity in British Columbia: Our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. pp. 162-172.

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Rankin, C. 2004. Invasive alien species framework for BC: identifying and addressing threats to biodiversity: a working document to address issues associated with biodiversity in British Columbia. Biodiversity Branch, British Columbia Ministry of Water, Land and Air Protection. Victoria, BC. 108 p.

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Footnote 105

Martin, M. 2003. Common reed (Phragmites australis) in the Okanagan Valley, British Columbia, Canada. Victoria, BC. Botanical Electronic News,

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Footnote 106

Brothers, K., Ceska, A., Colangeli, A., Coupé, R., Fairbarns, M., Fenneman, J., Ganders, F., Grilz, P., Klinkenberg, B., Klinkenberg, R., Lewis, G., Penny, J. and Whitton, J. 2013. E-Flora BC: Electronic atlas of the plants of British Columbia [online]. Lab for Advanced Spatial Analysis. (accessed 22 May, 2013).

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Footnote 107

Southern Interior Weed Management Committee. 2013. Thompson-Nicola Regional District noxious weed control programs [online]. (accessed 7 May, 2013).

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Campbell, R.W., Dawe, N.K., McTaggart-Cowan, I., Cooper, J.M., Kaiser, G.W., McNall, M.C.E. and Smith, G.E.J. 1997. The birds of British Columbia, volume 3: passerines - flycatchers through vireos. UBC Press. Vancouver, BC. 693 p.

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Voller, J. and McNay, R.S. 2007. Problem analysis: effects of invasive species on species at risk in British Columbia. FORREX Series No. 20. FORREX Forest Research Extension Partnership. Kamloops, BC. 145 p.

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Footnote 110

Herborg, M. 2011. Aquatic Invasive Species Coordinator, British Columbia Ministry of Environment. Victoria BC. Unpublished data.

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Footnote 111

Rae, R. 2005. The state of fish and fish habitat in the Okanagan and Similkameen basins. Canadian Okanagan Basin Technical Working Group. Westbank, BC. 125 p.

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Footnote 112

Johnson, E.E. 2009. A quantitative risk assessment model for the management of invasive yellow perch in Shuswap Lake, British Columbia. Thesis (Master of Resource Management). Simon Fraser University, School of Resource and Environmental Management. Burnaby, BC. 94 p.

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Footnote 113

Freshwater Fisheries Society of BC. 2004. Rainbow trout strains currently stocked in BC waters. Freshwater Fisheries Society of BC. iii + 22 p.

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Footnote 114

Hirner, J.L.M. 2006. Relationships between trout stocking and amphibians in British Columbia's southern interior lakes. Thesis (Master of Resource Management). Simon Fraser University, School of Resource and Environmental Management. x + 118 p.

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Footnote 115

Northcote, T. 1991. Success, problems, and control of introduced mysid populations in lakes and reservoirs. American Fisheries Society Symposium 9:5-16.

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Footnote 116

Whall, J. and Lasenby, D. 2000. Comparison of the trophic role of the freshwater shrimp (Mysis relicta) in two Okanagan Valley lakes, British Columbia. In Okanagan Lake action plan year 4 (1999) report. Edited by Andrusak, H., Sebastian, D., McGregor, I., Matthews, S., Smith, D., Ashley, K., Pollard, S., Scholten, G., Stockner, J., Ward, P., Kirk, R., Lasenby, D., Webster, J., Whall, J., Wilson, G. and Yassien, H. BC Ministry of Agriculture, Food and Fisheries. Victoria, BC. pp. 259-277.

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Footnote 117

Andrusak, H. 2008. Okanagan Lake action plan years 11 (2006) and 12 (2007) with reference to results from 1996-2007. In Okanagan Lake Action Plan, Years 11 (2006) and 12 (2007) Report. Fisheries Project Report No. RD124. Edited by Andrusak, H., Andrusak, G., Matthews, S., Wilson, A., White, T., Askey, P., Sebastian, D., Scholten, G., Woodruff, P., Webster, J., Vidmanic, L. and Stockner, J. BC Ministry of Environment. Victoria, BC. pp. 1-24.

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Footnote 118

Schindler, D.E., Carter, J.L., Francis, T.B., Lisi, P.J., Askey, P.J. and Sebastian, D.C. 2012. Mysis in the Okanagan Lake food web: a time-series analysis of interaction strengths in an invaded plankton community. Aquatic Ecology 46:215-227.

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Footnote 119

Andrusak, H. and White, W. 2008. Results of Mysis relicta experimental commercial fishery on Okanagan Lake, 2006 and 2007. In Okanagan Lake Action Plan, Years 11 (2006) and 12 (2007) Report. Fisheries Project Report No. RD124. Edited by Andrusak, H., G.Andrusak, S.Matthews, A.Wilson, T.White, P.Askey, D.Sebastian, G.Scholten, P.Woodruff, J.Webster, L.Vidmanic and J.Stockner. BC Ministry of Environment. Victoria BC. pp. 249-275.

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Footnote 120

Dunbar, G. 2009. Management plan for eurasian watermilfoil (Myriophyllum spicatum) in the Okanagan, British Columbia. Okanagan Basin Water Board. 62 p.

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Footnote 121

BC Ministry of Agriculture. 2013. Aggressive ornamentals, saltcedar [online]. (accessed 7 May, 2013).

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Footnote 122

Parish, R., Coupé, R. and Lloyd, D. (eds.). 1996. Plants of southern interior British Columbia. Ministry of Forests and Lone Pine Publishing. Vancouver, BC. 462 p.

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Footnote 123

Elliott, J.E., Machmer, M.M., Wilson, L.K. and Henny, C.J. 2000. Contaminants in ospreys from the Pacific Northwest: II. Organochlorine pesticides, polychlorinated biphenyls, and mercury 1991-1997. Archives of Environmental Contamination and Toxicology 38:93-106.

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Footnote 124

Gill, H., Wilson, L.K., Cheng, K.M. and Elliott, J.E. 2003. An assessment of DDT and other chlorinated compounds and the reproductive success of American robins (Turdus migratorius) breeding in fruit orchards. Ecotoxicology 12:113-123.

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Footnote 125

Elliott, J.E., Martin, P.A., Arnold, T.W. and Sinclair, P.H. 1994. Organochlorines and reproductive success of birds in orchard and non-orchard areas of central British Columbia, Canada, 1990-91. Archives of Environmental Contamination and Toxicology 26:435-443.

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Footnote 126

Rae, R. and Jensen, V. 2007. Contaminants in Okanagan fish: recent analyses and review of historic data. Okanagan Nation Alliance Fisheries Department. Westbank, BC. 48 p.

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Footnote 127

Drury, C.F., Yang, J.Y. and De Jong, R. 2011. Trends in residual soil nitrogen for agricultural land in Canada, 1981-2006. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 15. Canadian Councils of Resource Ministers. Ottawa, ON. iii + 16 p.

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Footnote 128

BC Ministry of Environment. 2003. Water quality objectives for Okanagan Lake: overview. Update to the report: Phosphorus in the Okanagan Valley lakes: sources, water quality objectives and control possibilities (1985). British Columbia Ministry of Environment.

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Footnote 129

Lakeshore Environmental Ltd. 2002. Environmental impact study on discharge options, liquid waste management plan main arm, Shuswap Lake. 51 p.

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Footnote 130

Northwest Hydraulic Consultants. 13 A.D. 2011 Shuswap and Mara lakes water quality report. Prepared for the Shuswap Lakes Integrated Planning Process and the Fraser Basin Council. 160 + App. p.

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Footnote 131

Infrastructure Canada. 2013. Canada and BC partner to improve water quality in Sicamous and Mara Lake [online]. (accessed 5 September, 2013).

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Footnote 132

Jensen, V. and Suzuki, N. 2011. Personal communication. Senior environmental impact biologist (VJ), Ministry of Environment, Penticton BC; air quality science specialist (NS), Ministry of Environment, Victoria, BC.

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Footnote 133

Phippen, B.W., Parks, D.C., Swain, L.G., Nordin, R., McKean, C.J.P., Holms, G.B., Warrington, P.D., Nijman, R., Deniseger, J. and Erickson, L. 1996. A ten-year assessment of water quality in six acid-rain-sensitive British Columbia lakes (1984-1994). BC Ministry of Environment, Lands and Parks.

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Footnote 134

Zhang, X., Brown, R., Vincent, L., Skinner, W., Feng, Y. and Mekis, E. 2011. Canadian climate trends, 1950-2007. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 5. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 21 p.

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Footnote 135

Cannon, A., Lai, T. and Whitfield, P. 2011. Climate-driven trends in Canadian streamflow, 1961-2003. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 19. Canadian Councils of Resource Ministers. Ottawa, ON. Draft report.

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Footnote 136

Hamann, A. and Wang, T. 2006. Potential effects of climate change on ecosystem and tree species distribution in British Columbia. Ecology 87:2773-2786.

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Footnote 137

Gayton, D.V. 2008. Impacts of climate change on British Columbia's biodiversity: a literature review. FORREX Forest Research Extension Partnership. Kamloops, BC. 24 p.

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Footnote 138

Brewer, R., Cohen, S., Embley, E., Hamilton, S., Julian, M., Kulkami, T., Taylor, B., Tansey, J., VanWynsberghe, R. and Whitfield, P. 2004. Water management and climate change in the Okanagan Basin. Edited by Cohen, S. and Kulkarni, T. Environment Canada and University of British Columbia. 75 p.

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Footnote 139

Cohen, S., Neilsen, D. and Smith, S. 2004. Expanding the dialogue on climate change and water management in the Okanagan Basin, British Columbia: final report. Edited by Cohen, S., Neilsen, D. and Welbourn, R. Environment Canada, Agriculture and Agri-Food Canada. 257 p.

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Footnote 140

Merritt, W. and Alila, Y. 2004. Hydrology. In Expanding the dialogue on climate change and water management in the Okanagan basin, British Columbia. Edited by Cohen, S., Neilsen, D. and Welbourn, R. Environment Canada, Agriculture and Agri-Food Canada, and University of British Columbia. Vancouver, BC. pp. 63-88. .

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